Probing The Charm Yukawa Coupling At Future E-p And E~+e~-Colliders

Higgs boson,which is the last particle in the Standard Model,has been discovered with a mass of 125 GeV at the LHC in 2012.So far,since direct evidence for Yukawa couplings between all the 3rd generation charged fermions with Higgs boson has been provided by LHC,the next question we may be interested in is whether the mass of the first two generation charged fermions arise from exactly the same mechanism.To answer this question,direct measurements of charm or muon Yukawa couplings have good potential.However,probing the charm Yukawa is difficult at the LHC due to the severe QCD background and the sensitivity limits.This thesis compares the possibility of probing charm Yukawa coupling at the two proposed future "Higgs Factory",the Large Hadron electron Collider(LHeC)and Circular Electron Positron Collider(CEPC),by analyzing the signal and background and simulating using programs.At the LHeC,Higgs bosons will be produced via vector boson fusion(VBF)and the background may be suppressed significantly by the energetic forward jet However,suffering from huge ?-g scattering background,the potential of LHeC search is still limited:only about 4%signal-to-background and a significance of 2? are expected for ?c?1.18 with 3ab-1 integrated luminosity,using a-80%polarized electron beam of 60 GeV.In contrast,CEPC produces Higgs bosons via e+e-? Zh,and it can provide clean signals without complicated QCD background.So CEPC shows great potential to probe charm Yukawa since the measurement can reach a total signal-to-background of 66%and a significance of 5.8(8.0)? for ?c ? 1 with 2(5)ab-1 integrated luminosity.Moreover,the 2nd chapter of the thesis briefly summarizes the knowledge system of particle physics from one point of view,which,to some extent,shows the precision and elegance of the discipline.